1. Technical Field
The present invention relates to semiconductor memory devices and methods for manufacturing the same.
2. Related Art
It is important for semiconductor memory devices to prevent their plugs that electrically connect ferroelectric capacitors to semiconductor elements on a substrate from oxidation. A barrier layer composed of aluminum oxide or the like may be formed on side surfaces of a ferroelectric capacitor to prevent oxygen from penetrating the ferroelectric capacitor through its side. For example, JP-A-2003-110095 describes an example of related art. However, as the layer is additionally formed on the ferroelectric capacitor, a film forming step and a step of patterning the film are added, which complicates the manufacturing process. Also, as the barrier layer is additionally provided, the size of the ferroelectric capacitor becomes larger, which interferes with device miniaturization.